I agree .They do need to make a new dude.

Well, I had an Idea for a character. Here's a story line for him.

MAIM

During the outworld invasion by shao kahn, the tarkatan warriors raided the earth in a bloody rage. One of them captured and raped an earth-born woman. Though she died, her offspring lived. The result was a hybrid; a half human, half tarkatan being who goes by the name of "Maim." His face is of a normal human, but his steel skeleton contains the blades of a tarkatan warrior. His rage comes from vengence, never resting until he finds the killer of his only family. It eventually earned him a place as one of the chosen, but is not allowed in their camp, simply because of his unpredictable blood fits.

Right, Armaggon.

Anyway, I dont see why they need a new dude. Original characters are hardly ever popular in the world of video game adaptations (For example, Resident Evil's Alice). It's not like MK doesn't have enough bad guys already.
New dude not needed, dude.

There is such huge spin off potential. Like MK Mythologies for Sub-Zero that could be a movie with the right director. There are enough women in it or even MK Mythologies Scorpion.

Make a movie with Kabal, an unseen character from Annihilation. He was an evil Black Dragon until the extermination squads changed it by almost killing him. Left for dead he becomes a reluctant hero to challenge the leader of the extermination squads. Because Kahn and Motoro have been in previous movies why not have Kintaro?

Kabal can be joined by two evil allies, Kira and Kobra. Kabal is driven by revenge, Kira is driven by money and Kobra is driven by lust for combat and lust for Kira. There can be an extra dichodamy with the special forces as they hunt for the Black Dragon and the members of the Black Dragon hunt the extermination squad for revenge for Kabal. All the time unknowingly saving humanity from the extermination squads.

Good idea? Bad idea? You don't need a new dude, you just need to tell a different story.